How Do We Learn From Our Mistakes?

When things are discovered to have gone wrong, how do they get investigated? And then how is change and learning brought in to make sure that the same mistakes don't happen twice? Well, not enough, i would say. There's oversea gap there. Smaller incidents that are less well known, it's harder to learn from them. Necessarily, a lot of local accidents,. most local accidents are small, course, and so they don't get reported.